[llvm] 0d19739 - [RISCV] Don't overcount FP constants in lowerBUILD_VECTOR

[Philip Reames via llvm-commits]

Author: Philip Reames
Date: 2023-05-03T12:21:18-07:00
New Revision: 0d19739768d46b8e07d4fa44aea901a19ad8cd8d

URL: https://github.com/llvm/llvm-project/commit/0d19739768d46b8e07d4fa44aea901a19ad8cd8d
DIFF: https://github.com/llvm/llvm-project/commit/0d19739768d46b8e07d4fa44aea901a19ad8cd8d.diff

LOG: [RISCV] Don't overcount FP constants in lowerBUILD_VECTOR

If the value count is > 1, we use a splat and thus only materialize the constant once, not once per element.

Added: 
    

Modified: 
    llvm/lib/Target/RISCV/RISCVISelLowering.cpp

Removed: 
    


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diff  --git a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
index 4eae05fa6e4d..336cbfc93874 100644
--- a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -3161,9 +3161,9 @@ static SDValue lowerBUILD_VECTOR(SDValue Op, SelectionDAG &DAG,
 
     ValueCounts.insert(std::make_pair(V, 0));
     unsigned &Count = ValueCounts[V];
-
-    if (auto *CFP = dyn_cast<ConstantFPSDNode>(V))
-      NumScalarLoads += !CFP->isExactlyValue(+0.0);
+    if (0 == Count)
+      if (auto *CFP = dyn_cast<ConstantFPSDNode>(V))
+        NumScalarLoads += !CFP->isExactlyValue(+0.0);
 
     // Is this value dominant? In case of a tie, prefer the highest element as
     // it's cheaper to insert near the beginning of a vector than it is at the